linux-stable/fs/compat_binfmt_elf.c
Kees Cook 9e1a3ce0a9 binfmt_elf: Introduce KUnit test
Adds simple KUnit test for some binfmt_elf internals: specifically a
regression test for the problem fixed by commit 8904d9cd90ee ("ELF:
fix overflow in total mapping size calculation").

$ ./tools/testing/kunit/kunit.py run --arch x86_64 \
    --kconfig_add CONFIG_IA32_EMULATION=y '*binfmt_elf'
...
[19:41:08] ================== binfmt_elf (1 subtest) ==================
[19:41:08] [PASSED] total_mapping_size_test
[19:41:08] =================== [PASSED] binfmt_elf ====================
[19:41:08] ============== compat_binfmt_elf (1 subtest) ===============
[19:41:08] [PASSED] total_mapping_size_test
[19:41:08] ================ [PASSED] compat_binfmt_elf ================
[19:41:08] ============================================================
[19:41:08] Testing complete. Passed: 2, Failed: 0, Crashed: 0, Skipped: 0, Errors: 0

Cc: Eric Biederman <ebiederm@xmission.com>
Cc: David Gow <davidgow@google.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Magnus Groß" <magnus.gross@rwth-aachen.de>
Cc: kunit-dev@googlegroups.com
Cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
v1: https://lore.kernel.org/lkml/20220224054332.1852813-1-keescook@chromium.org
v2:
 - improve commit log
 - fix comment URL (Daniel)
 - drop redundant KUnit Kconfig help info (Daniel)
 - note in Kconfig help that COMPAT builds add a compat test (David)
2022-03-03 20:38:56 -08:00

144 lines
3.8 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* 32-bit compatibility support for ELF format executables and core dumps.
*
* Copyright (C) 2007 Red Hat, Inc. All rights reserved.
*
* Red Hat Author: Roland McGrath.
*
* This file is used in a 64-bit kernel that wants to support 32-bit ELF.
* asm/elf.h is responsible for defining the compat_* and COMPAT_* macros
* used below, with definitions appropriate for 32-bit ABI compatibility.
*
* We use macros to rename the ABI types and machine-dependent
* functions used in binfmt_elf.c to compat versions.
*/
#include <linux/elfcore-compat.h>
#include <linux/time.h>
#define ELF_COMPAT 1
/*
* Rename the basic ELF layout types to refer to the 32-bit class of files.
*/
#undef ELF_CLASS
#define ELF_CLASS ELFCLASS32
#undef elfhdr
#undef elf_phdr
#undef elf_shdr
#undef elf_note
#undef elf_addr_t
#undef ELF_GNU_PROPERTY_ALIGN
#define elfhdr elf32_hdr
#define elf_phdr elf32_phdr
#define elf_shdr elf32_shdr
#define elf_note elf32_note
#define elf_addr_t Elf32_Addr
#define ELF_GNU_PROPERTY_ALIGN ELF32_GNU_PROPERTY_ALIGN
/*
* Some data types as stored in coredump.
*/
#define user_long_t compat_long_t
#define user_siginfo_t compat_siginfo_t
#define copy_siginfo_to_external copy_siginfo_to_external32
/*
* The machine-dependent core note format types are defined in elfcore-compat.h,
* which requires asm/elf.h to define compat_elf_gregset_t et al.
*/
#define elf_prstatus compat_elf_prstatus
#define elf_prstatus_common compat_elf_prstatus_common
#define elf_prpsinfo compat_elf_prpsinfo
#undef ns_to_kernel_old_timeval
#define ns_to_kernel_old_timeval ns_to_old_timeval32
/*
* To use this file, asm/elf.h must define compat_elf_check_arch.
* The other following macros can be defined if the compat versions
* differ from the native ones, or omitted when they match.
*/
#undef elf_check_arch
#define elf_check_arch compat_elf_check_arch
#ifdef COMPAT_ELF_PLATFORM
#undef ELF_PLATFORM
#define ELF_PLATFORM COMPAT_ELF_PLATFORM
#endif
#ifdef COMPAT_ELF_HWCAP
#undef ELF_HWCAP
#define ELF_HWCAP COMPAT_ELF_HWCAP
#endif
#ifdef COMPAT_ELF_HWCAP2
#undef ELF_HWCAP2
#define ELF_HWCAP2 COMPAT_ELF_HWCAP2
#endif
#ifdef COMPAT_ARCH_DLINFO
#undef ARCH_DLINFO
#define ARCH_DLINFO COMPAT_ARCH_DLINFO
#endif
#ifdef COMPAT_ELF_ET_DYN_BASE
#undef ELF_ET_DYN_BASE
#define ELF_ET_DYN_BASE COMPAT_ELF_ET_DYN_BASE
#endif
#ifdef COMPAT_ELF_PLAT_INIT
#undef ELF_PLAT_INIT
#define ELF_PLAT_INIT COMPAT_ELF_PLAT_INIT
#endif
#ifdef COMPAT_SET_PERSONALITY
#undef SET_PERSONALITY
#define SET_PERSONALITY COMPAT_SET_PERSONALITY
#endif
#ifdef compat_start_thread
#define COMPAT_START_THREAD(ex, regs, new_ip, new_sp) \
compat_start_thread(regs, new_ip, new_sp)
#endif
#ifdef COMPAT_START_THREAD
#undef START_THREAD
#define START_THREAD COMPAT_START_THREAD
#endif
#ifdef compat_arch_setup_additional_pages
#define COMPAT_ARCH_SETUP_ADDITIONAL_PAGES(bprm, ex, interpreter) \
compat_arch_setup_additional_pages(bprm, interpreter)
#endif
#ifdef COMPAT_ARCH_SETUP_ADDITIONAL_PAGES
#undef ARCH_HAS_SETUP_ADDITIONAL_PAGES
#define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1
#undef ARCH_SETUP_ADDITIONAL_PAGES
#define ARCH_SETUP_ADDITIONAL_PAGES COMPAT_ARCH_SETUP_ADDITIONAL_PAGES
#endif
#ifdef compat_elf_read_implies_exec
#undef elf_read_implies_exec
#define elf_read_implies_exec compat_elf_read_implies_exec
#endif
/*
* Rename a few of the symbols that binfmt_elf.c will define.
* These are all local so the names don't really matter, but it
* might make some debugging less confusing not to duplicate them.
*/
#define elf_format compat_elf_format
#define init_elf_binfmt init_compat_elf_binfmt
#define exit_elf_binfmt exit_compat_elf_binfmt
#define binfmt_elf_test_cases compat_binfmt_elf_test_cases
#define binfmt_elf_test_suite compat_binfmt_elf_test_suite
/*
* We share all the actual code with the native (64-bit) version.
*/
#include "binfmt_elf.c"